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We describe the frequency shifts for trapped fermions, as in a optical lattice clock. We discuss the behavior of the shift and show that it is not proportional to the difference of partial densities, in contrast to previously observed clock shifts. We provide a simple counter-example and also show that large interactions may effectively cancel the frequency shifts due to collisions.
We developed a theoretical method within the framework of relativistic many-body theory to accurately treat correlation corrections in atoms with few valence electrons. Preliminary results for systems of interest to atomic clock development are reported. We also calculated the blackbody radiation shift of the ground-state hyperfine microwave transition in 87Rb using the relativistic all-order method...
For cold samples of laser-cooled atoms to be useful in emerging technologies such as compact atomic clocks and sensors, it is necessary to achieve small sample sizes while retaining a large number of cold atoms. Achieving large atom numbers in a small system is a major challenge for producing miniaturized laser-cooled atomic clocks, since the number of captured atoms in a vapor-cell magneto-optical...
Trapped ion clocks derive information from a reference atomic transition by repetitive interrogations of the same quantum system, either a single ion or ionized gas of many millions of ions. Atomic beam frequency standards, by contrast, measure reference atomic transitions in a continuously replenished “flow through” configuration where initial ensemble atomic coherence is zero. We will describe some...
We report measurements and calculations of distributed cavity phase errors in an atomic fountain clock. We isolate even and odd symmetry contributions to the distributed cavity phase shift and measure their characteristic power dependences. The measurements and model largely agree with no free parameters. Verification of the model\ will enable a reduction of the distributed cavity phase uncertainty...
An uncertainty evaluation of NRC's cesium fountain clock FCs1 is currently being performed. One task of this evaluation consists in quantifying the contribution to the frequency uncertainty, the second-order Zeeman shift. We report the results obtained from measurements of the C-field above the Ramsey cavity using the Larmor frequency as a probe. This technique is possible because a transverse C-field...
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